Valveless chemical heater



NOV. 5, 1940. D F OTHMER 2,220,777'

vALvELEss CHEMICAL HEATER Filed Feb. l, 1959 3 Sheets-Sheet l ATTORNEYNov. s, 1940. D, F OTHMER' 2220,777

VALVELESS CHEMICAL HEATER Filed Feb. 1, 1939 3 S'heets-Sheet 2 ATTORNEYNOV. 5, 1940. D |Q||||V|ER 2,220,777

vALvELEss CHEMICAL HEATER Filed Feb. 1, 1939 5 Sheets-Sheet 3 INVEN-rogwaa/d JY' f/n'ner BY waa ATTORNEY 0 zml m f Patented Nov.

UNITED ysfraras f PATENT OFFICE vanvamss chameau HEATER Donald F.Othmer, Coudersport, Pa. Appunti@ February 1, 1939,v serial No. 253,949

i Claims.. (C l. 126-204) This invention generally relates tohermetically sealed chemical'heater units suitable for the same.purposes as the hot water bottles now commonly existent or like devicesemploying heat, and

5 :herein heat of crystallization .generates the eat.

Heretofore varied forms of chemical heaters have -been suggestedparticularly those employing supersaturated solutions of sodium acetate10 where heat was developed yby crystallizing the solution, but all ofthese heaters have been objectionable because they have had lopeningsAtherein; namely, these heaters had apertures through which a seedcrystal could be introduced i5 to stm thecrystamzauon, or had valvesausw'- ing the introduction oi' air or of solid crystal to commence thecrystallization process. Ifair was introduced through the valve, incertain instances avalvestemwasprovideduponwhichathin 20 layer of thecrystalline solution dried into solid crystals which latter, bymanipulation, would be later dropped into the solutionto lire the same.All oi the former containers which employed the heat or crystallizationof supersatu'rated so- 25lutious,wereopentooneormoreoftheti'ollrm-` insobjections:- (1) '111e leaked s olutions, clogging the valves and makingmovements bili; required repeated mi `lllid (4)Solidcrystalsitoseedthesoiutions'werenotai- Mconvenimtlyathand. il.,itisanobjectdmyinventinnto eliminateailvalvesopmlmammchclnsoi'"heaters.

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It is a further objects! my-inventiontoptovide'suchchemicalheaterswithapleormetaiinteriorlyotthesamesothatthemetalwiil 1 and a:

and so that objects in contact with the heater. or encompassed therebyin whole or in part, will receive a predetermined amount of heat.

It is a further object of my invention to provide such chemical heatersinthe i.'orm of vbody 5 cal heaters in which heat is generated fromcrysl5 tallizing supersaturated solution, and which is preferably iiredlby a metallic rubbing action occurring' within the container, but whichmay be red, it desired, through other rubbing A s 4means and possiblycertain vibrations. 2Q It is a tlnther object to provide an economicaland convenient form or sheet metal hotwater r bottle which is feasible'for quantity production Withtheseandihetobjectsinview'thein-'.ventionconsists in the construction and novel combination and, ent'o!parts; herein` described, illustrated in the Iugeimi-V "panyingdrawings'in reference to specific em-VYboriimeuisthfereoi,igimipoiutedout-intheclaims M hereto appended. itbeing understood that yar!- 1 narmamr bottiV myinvention;

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111g'.4in-averties!orarurtlieu'-V Hon-ot thehot waterbottleshowninParksmania-eenmaal heatertohtmilkbottlesrrblblel:

containerandhavlngamhlmnh awlm l Itisafactknowntophysicalchemiststhatthepresence of an impurity in a liquid material lowers the temperature atwhich crystallization occurs. Thus namely, the freezing point of wateris lowered by the presence of ordinary salt, or in other words the wateris less apt to crystallize, Aor is more .stable In order to obtain thedesired stability in the solution, I have found that it is desirable tointroduce certain impuritiesin the sodium acetate or other suitablesolution, whereas in the past attempts have been made tol utilize highlypure solutions of the respective salts. I have discovered that puresolutions are undesirable because they are less stable .than more impuresolutions. For example, if sodium acetate is used as the crystallizingsalt, I have found that a small amount o i sodium formate, sodiumpropionate, sodium butyrate, or anyone or more ofthe sodium salts of thehomologous series oi acids to which acetic belongs, is eiective' instabilizing the salt solution so that it will not crystallize underconditions of cooling below room temperature or of rough handling.Furthermore, I have found that under some conditions of purification thesodium acetate made from the relatively impure acetic acid containingall of the above mentioned sodium salts and. certain other impurities isvdesirable as such a because of the impurities which it naturallycontains. A material soformed and used in conjunction with the known artis found to be considerably more stable so as to allow the cooling'ofthe solution to the freezing. point and considerable rough handling.

Generally speaking the amounts of sodium salts ofacids other thanaceticmentioned should be not more than two or threeper cent of the total nmaterial. Also, small amounts of sodium carbonate or sodium hydroxidemay be present in the sodium acetate and these also may likewiseincrease stability. Also, I have found that sodium acetate prepared fromacetic acid obtained in wood distillation is suitable for use in myheaters and the impurities which are naturally prent inthesodimnaetatepreparedinthiswaygreatly increase the stability of theproduct. Thus, a

lower grade of acetic acid anda cheaper form of sodium acetate may beutilized than hithert Vthere'areknnwntobetracesofcertainotherllia-Aterlalssuchasalcohols,esters,ketones,cresols,

andotherorganicchemicalswhichareprescnt unchangedbytheneutralisationprooess. These.'

traces of organic matterhavebeenfound-to in-I crease the stability ofthe liquid solution, inmyheaters'` Inthe varlant forms ofmyinvuitionsholnin Figs. 'I-l4, Eig'. 'l illustrates a-container'llseuferallysimilartothe containershownin 1|1g.'1,

except that top'and bottom portions Il andpl may besoldered together,as'at 8l. ilishereillusiratedas provided witha vertically tiring trigger82, having ahook" mdasatilwhichextendsdomiwardtnanopen-.- ing'ilincircularblock Il ofsodium acetate inbottom portlonltthetop' water inthedesired proportions. The block 68 with by being immersed therein.

standard rubber'hot water bottles.

portion Il permanently aiiixed'A thereto: the

heater can then be made ready for use by being boned in minus. water forapproximately ten minutes, subsequently cooled, and maybe then is achemical heater for warming' liquid solutions.

and aording an eilicient heat exchange there-V Fig. 9 illustrates aiiber board, or other convenient form of insulated container 14 having4a removable chemical heater unit 18 therein, the

similar to that shown in Fig. l except that there is a middle partition84 dividing. the unit 82 intoy two compartments 86 and 88 respectively,there.

being two individual firing mechanisms provided,

indicated 'as 80 respectively, thereby providing an integral unit. 82having two compartments which may be nred one after the other, givingheat for a longer time than the Aunit shown in Fig. l.

Fig. 11 is'a fragmentary cross-section of a preierably flexible sidedrubber 'bottle 82 having a stopper 94 with a exible portion 98. Thestopper 8l may be provided with a metal collar 98 having a partition|88, a -spring- |82, and a metal scraping armv I 8l, all as clearlyindicated in the said iigure. It .will be recognized that stopper means98, providing. metal friction device as indicated, may be adapted tovarious types of containers, iie'xible w'alledor not as desired.- whichmay be iilled'with a salt solution and the .iiring stopper meansassociated therewith; in fact, such "rlng" stopper means could beutilized with Fig. 12 shows an alternate formfor a fully flexible sidedcontainer and indicates in cross-sec-k tional view a rubber container|88 of generally rectangular cross-section and provided with two metalinserts-188 and ||8 respectively, so positlonedJll 01113081138 Wallsjhatthetwu may be.

brought together and ulation oftheuser.

Fig. 13 illustrates in vertical on an `integral metal unit |12, ofcommontin can type,

scraped by proper manipwith lock seamed portions as indicated at lI M.nA'

manen is indicated at ne to provide a seperate liquid comparhnent III,suitable for holding, for

example, liquid soup, as indicated, and a lower compartment .|28 for thechemical heater solutbn |22 and :Bring mechanism lndicatddas |28.

iig. 14 illustrates generally triple compartmented unit suitable-forpicnic lunches or the like, having a heater unit indicated generally as|28, a compartment for liquids or other materials to be heated indicatedas |28, above heater imit |28, and a storage compartment |38 suitablyinsulated as still from compartments |28 and |28,

Although r have described a spense form or and theuse of sodium acetateplus certain impuritiesin detail, it isobvious that certain othersaltsand may be utilized in either pure or' slightly impure `iorm for theheating uniis. Inessence my invention includes the use in hermeticaliycled containers of a :m '-1. ted solution of sodium acetate in slightlyimpure form which is adapted t0 generate aheat o! crystallization, andthe startingcf crysvarious modincations ci invention `may he made bythose skilledln the ar't vincluding the utilization of other iorms'of.containers, the starting of thefcrystallization or iiring" possibly byvibrations, includins sonic vibrations, and also the placing of variouspieces of metal within-a container which contains a supersaturated saltsoluboilings and crystallizations of the solution that tion and thestarting of the crystallization by merely shaking the container. Also bymaking chemical heaters with two or more self-contained cells, each withits individual firing means, it is apparent that sustained heats can beobtained from such chemical heaters. Also if desired a three or fourlegged tripod form of firing/mech@ anism maybe placed within the shell,arranged under slight tension and so that with repeated heater formed ofa substantially rigid metal shell having an integral flexible diaphragmand which includes a supersaturated salt solution Within-- the heaterwhich causes the temperature oi the unit to rise when crystaihzed, andmeans which upon manual manipulation oi the flexible dieH phragm withoutopening Athe container are adapted to cause e, metal to metal frictionwithin the container, thereby erystailiing said solution.

2. permanently closed and hermetically sealed chemical heater whichincludes a substam tially metal shell iorrceel of two generally assiemecircular portions each having a convex cross-seci tion, a e'xiblediaphragm in one of said'portions, a supersatureted salt solution havingheat of crystallization within said heater,and metal friction meanslarrangeci to scrape a wall of the container upon manual manipulation ofsaid diavhrew- 3. A heater as defined in claim 2 which additionallyincludes a permanently capped and hermetically sealed filling orificefor said heater.

4. A heater as dened in claim 2 wherein said diaphragm is vdepressedbelow the convex surface of the .portion o! the heater of which'it formsa part, thereby ahordinga degree of protection to the heater againstaccidental discharge. Y

5. A permanently closed and hermetically sealed chemical heater whichincludes a substantially rigid metal shell body, a exible diaphragmportion formed integrally in said substantially rigid metal shell body,a supersaturated salt solution having heat of crystallization withinsaid 6. A- structme es dened in claim 5 wherein said dexlble. diaphragmis formed by means of concentric grooves and ridges formed in the rigid.VWalle-:d metal Jody 7. A structure es dedned in claim 5 wherein seidmetal friction means comprises s metal mem har movable by seid diapamand extending irem one side of the container to another, said metallmerano-.r heinz; sss-ld internally to a portion the heater. 1

l ED'AL'D Y @TREK

